How does excess sodium affect the body

One systematic review of patients diagnosed with CKD found that high sodium intakes of greater than 4, mg a day were associated with progression of CKD, but low sodium intakes less than 2, mg a day had no significant effect when compared with moderate sodium intakes of 2,, mg a day.

Guidelines generally advise a moderate rather than low sodium restriction to prevent the development and progression of CKD. A daily sodium intake of less than 4, mg is recommended for overall management of CKD, and less than 3, mg daily for CKD with symptoms of fluid retention or proteinuria, a condition in which excess protein is excreted in the urine.

The amount of calcium that your body loses via urination increases with the amount of salt you eat. If calcium is in short supply in the blood, it can leach out of bones. So a diet high in sodium could have an additional unwanted effect—the bone-thinning disease known as osteoporosis. Research shows that a higher intake of salt, sodium, or salty foods is linked to an increase in stomach cancer. Almost any unprocessed food like fruits, vegetables, whole grains, nuts, meats, and dairy foods is low in sodium.

Most of the salt in our diets comes from commercially prepared foods, not from salt added to cooking at home or even from salt added at the table before eating. The most widely used, table salt, is extracted from underground salt deposits. It is heavily processed to remove impurities, which may also remove trace minerals. It is then ground very fine.

Iodine , a trace mineral, was added to salt in to prevent goiter and hypothyroidism, medical conditions caused by iodine deficiency. Table salt also often contains an anticaking agent such as calcium silicate to prevent clumps from forming. Kosher salt is a coarsely grained salt named for its use in traditional Kosher food preparation.

Kosher salt does not typically contain iodine but may have an anti-caking agent. Sea salt is produced by evaporating ocean or sea water. It is also composed mostly of sodium chloride, but sometimes contains small amounts of minerals like potassium, zinc, and iron depending on where it was harvested.

Because it is not highly refined and ground like table salt, it may appear coarser and darker with an uneven color, indicating the remaining impurities and nutrients. Unfortunately, some of these impurities can contain metals found in the ocean, like lead.

The coarseness and granule size will vary by brand. Himalayan pink salt is harvested from mines in Pakistan. Its pink hue comes from small amounts of iron oxide. Similar to sea salt, it is less processed and refined and therefore the crystals appear larger and contain small amounts of minerals including iron, calcium, potassium, and magnesium. Larger, coarser salt granules do not dissolve as easily or evenly in cooking, but offer a burst of flavor.

They are best used sprinkled onto meats and vegetables before cooking or immediately after. They should not be used in baking recipes. Keep in mind that measurements of different salts are not always interchangeable in recipes. Generally, sea salt and table salt can be interchanged if the granule size is similar.

However, table salt tends to have more concentrated, saltier flavor than kosher salt, so the substitution is one teaspoon of table salt for about 1. A deficiency of sodium in the U. Hyponatremia is the term used to describe abnormally low amounts of sodium in the blood. This occurs mainly in older adults, particularly those living in long-term care facilities or hospitals who take medications or have health conditions that deplete the body of sodium, leading to hyponatremia.

Excess vomiting, diarrhea, and sweating can also cause hyponatremia if salt is lost in these fluids that are expelled from the body. Sometimes too much fluid abnormally collecting in the body can lead to hyponatremia, which might stem from diseases such as heart failure or liver cirrhosis.

That also led the mice to eat more. These salt-driven changes in metabolism may thus partly explain why high salt diets have been linked to diabetes, heart disease, and other health problems that can result from the condition known as metabolic syndrome. More work will be needed to better understand these mechanisms. References: Increased salt consumption induces body water conservation and decreases fluid intake.

J Clin Invest. Epub Apr PMID: High salt intake reprioritizes osmolyte and energy metabolism for body fluid conservation. Site Menu Home.

The resulting increase in fluid intake can cause you to urinate more than usual. Hypernatremia can cause water to leach out of your cells and into your blood, in an attempt to dilute the excess sodium. If left untreated, this fluid shift can result in confusion, seizures, coma, and even death 2 , 7. Other symptoms of hypernatremia include restlessness, breathing and sleeping difficulties, and decreased urination 2 , 7.

Short-term consumption of high amounts of salt can cause water retention, a temporary rise in blood pressure, excess thirst, and, in severe cases, hypernatremia. However, some people may experience little side effects. For instance, two large reviews report that a reduction in salt intake of 4. However, the observed reductions were close to two times larger in individuals with high blood pressure, compared with those with blood pressure in the normal range 8 , 9.

Moreover, these effects are thought to be significantly stronger in salt-sensitive individuals than in those who are not salt-sensitive. Obesity and aging are also though to amplify the blood pressure-raising effects of salt-rich diets 3.

Several studies link a high salt diet to a higher risk of stomach cancer 10 , 11 , Another study further suggests that people with high salt intakes may have a two times higher risk of stomach cancer than those with lower intakes. However, experts believe that salt-rich diets may make a person more vulnerable to stomach cancer by causing ulcers or inflammation of the stomach lining The link between salt-rich diets, heart disease, and premature death is still somewhat controversial.

Some studies suggest that high salt intakes cause a rise in blood pressure and a stiffening of blood vessels and arteries. In turn, these changes may result in a higher risk of heart disease and premature death 3 , 15 , 16 , 17 , For instance, one year study notes that participants who consumed less than 5.

However, others suggest that high salt diets have no effects on heart health or longevity and that low salt diets may actually increase the risk of heart disease and death 20 , 21 , 22 , 23 , These differing study results may be explained by differences in study design, methods used to estimate sodium intake, and participant factors, such as weight, salt sensitivity, and the other health issues participants may be facing 3 , Eating too much salt in the long term may raise your blood pressure and increase your risk of stomach cancer.

It may also increase the risk of heart disease and premature death, although more research is needed to confirm this. Fatal salt overdoses are rare, as they require people to consume amounts of salt nearing 0.

Silver Spring, MD: U. Food and Drug Administration; Accessed August 31, Department of Agriculture, U. Department of Health and Human Services. Dietary Guidelines for Americans, — external icon , 9th ed. December Accessed January 29, Prevalence of sodium intake in the United States external icon.

Estimated hour urinary sodium and potassium excretion in US adults. Briefel R, Johnson C. Secular trends in dietary intake in the United States external icon. Annu Rev Nutr. Sources of sodium in U. Reduced dietary salt for the prevention of cardiovascular disease external icon.